Changes
in the abundance of Lynx (Lynx canadensis) [top] and
various prey
species such as Snowshoe Hare
(Lepus
americanus) are documented in records of the
numbers of pelts
brought
into the Hudson Bay Company. Note that the Lynx cycle peaks
slightly
later
than the hare cycle. This suggests a hypothesis that an abundance
of
hares
feeds an increase in the number of lynx, which in turn depresses
the
number
of hare and so on. [Unfortunately, hares also cycle in the absence
of
lynx].
The original data set was compiled by Charles Elton, and is
notable as one of the longest time series in ecology.